<?php
header('Content-Type: text/xml');
function curl_get_file_contents($URL)
{
        $c = curl_init();
        curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($c, CURLOPT_URL, $URL);
        $contents = curl_exec($c);
        curl_close($c);

        if ($contents) return $contents;
            else return FALSE;
 }

$xmlString = curl_get_file_contents("http://cbio.mskcc.org/biogene/retrieve.do?query=".$_GET['query']."&org=".$_GET['org']."&retstart=".$_GET['retstart']."&retmax=".$_GET['retmax']."");
echo $xmlString;
?>